207 research outputs found
Isotopic dependence of reaction cross sections for Fe and Sn nuclei
The reactions play an important role for the energy generation
and the synthesis of chemical elements in the stars, as well as for nuclear
engineering and medical applications. The aim of this study is to explore the
evolution of reactions in Fe and Sn isotope chains in order to
assess their properties with the increase of neutrons in target nucleus, and
compare with other relevant neutron induced reactions. Model calculations of
the cross sections are based on the statistical Hauser-Feshbach model in TALYS
implementation, using global optical model potential that is additionally
adjusted by the cross section data for Fe and Sn.
The calculations of reactions in Fe and Sn isotopes provide the
insight into their isospin dependence and properties over the complete relevant
range of neutron energies. The results show the evolution of the cross sections
with pronounced maxima at low-mass isotopes, and rather strong decrease for
neutron-rich nuclei consistent with the reduction of the reaction -value and
increased contributions from other exit channels from compound nucleus. The
analysis of the Maxwellian averaged cross sections at temperatures in stellar
environment shows that while the reactions contribute for the
low-mass isotopes, in neutron induced reactions with nuclei with neutron
excess, and neutron emission dominate.Comment: 14 pages, 14 figure
INVESTIGATION OF CLASSROOM TEACHER CANDIDATES’ COGNITIVE STRUCTURES ON SOME BASIC SCIENCE CONCEPTS
In this study, it was aimed to investigate the cognitive structures of classroom teacher candidates on some basic science concepts. Word association test (WAT) technique was used to gather data. Twelve keywords related to basic physics, chemistry, and biology concepts were determined and used in the formation of WAT’s. Forty-three classroom teacher candidates studying at 2nd classes at an education faculty were the participants of this study. Data obtained by WAT were examined by using number of different responses given to each keyword, and by drawing concept maps according to both frequencies and relatedness coefficients. A cut-off point technique was used when drawing the concept maps. Because of this study, it can be said that participants have moderate cognitive structures on the investigated science concepts and their cognitive structure was strongest on chemistry concepts and weakest on biology concepts.  Article visualizations
Tissue Levels of CD80, CD163 and CD206 and Their Ratios in Periodontal and Peri-Implant Health and Disease
This study aimed to compare tissue levels of CD80 (pro-inflammatory macrophage-related surface marker), CD163, and CD206 (anti-inflammatory macrophage-related surface markers), and their ratios in periodontal and peri-implant health and disease. Altogether, 36 tissue samples were obtained from 36 participants with clinically healthy gingiva (n = 10), healthy peri-implant mucosa (n = 8), periodontitis lesions (n = 9), and peri-implantitis lesions (n = 9). CD80, CD163, and CD206 levels were assessed with immunoblotting. CD163 levels were found to be decreased (p = 0.004), and the CD80/CD163 ratio was found to be elevated (p = 0.002) in periodontitis lesions compared to healthy gingiva. Peri-implantitis lesions showed a tendency towards a higher CD80/CD163 ratio than in healthy peri-implant mucosa with a borderline difference (p = 0.054). No statistically significant difference was detected in CD80, CD163, and CD206 levels of periodontitis lesions when compared to peri-implantitis, and in healthy gingiva when compared to healthy peri-implant mucosa. A disruption in CD80/CD163 balance seems to be related to the pathogenesis of periodontitis and peri-implantitis, being less prominent in the latter. The reason behind this phenomenon may be either suppressed CD163 expression or reduced CD163+ anti-inflammatory macrophage abundance. </p
Aktivna deformacija Zemljine površine utvrđena preciznim nivelmanskim premjerom u Afyon-Akşehir grabenu u Zapadnoj Anadoliji u Turskoj
In the actively deforming region of western Anatolia, crustal deformation is accommodated by destructive earthquakes and a variety of aseismic events.
In this study, we investigated the 2016–2017 aseismic sequence located in the Bolvadin Fault, one of the segments of the Akşehir-Simav Fault System of western Anatolia by analysing surface deformation derived from detailed geological mapping. Our findings suggest that surface deformation in the Bolvadin Fault is accommodated by aseismic episodes. During the field studies in the Bolvadin area, progressive surface deformations, such as surface faults and earth fissures with a length of 800 meters to 3 kilometres and strike of N15°E to N70°E were mapped on a 1/5000 scale. Furthermore, a levelling network was established to calculate the vertical displacements and deformation rate along the surface deformations. Precision level measurements were undertaken in 2016 and 2017.
On the routes to the NW of the Bolvadin settlement, a vertical deformation rate of 30 mm/yr was detected in the period of 2016–2017, and a large deformation rate of 40 mm/yr was detected in the same period.Aktivna deformacija Zemljine kore se u regiji Zapadne Anadolije kompenzira razornim potresima i drugim seizmičkim događajima. U ovom smo radu na temelju detaljnog geološkog kartiranja analizirali deformaciju površine kako bismo proučili niza seizmičkih događaja u razdoblju 2016.–2017. na lokaciji rasjeda Bolvadin, jednoga od segmenata rasjednoga sustava Akşehir-Simav u Zapadnoj Anadoliji. Naši rezultati ukazuju na to da se površinska deformacije kompenzira tijekom aseizmičkih epizoda. Tijekom terenskih istraživanja u području Bolvadin, progresivne su površinske deformacije, poput površinskih rasjeda ili pukotina duljina od 800 m do 3 km, pružanja N15°E do N70°E, kartirane u mjerilu 1:5 000. Nadalje, uspostavljena je nivelmanska mreža kako bi se izmjerila brzina pomaka i deformacija. Precizna nivelmanska mjerenja izvedena su 2016. i 2017. godine. Na pravcima usmjerenima SZ od naselja Bolvadin, ustanovljena je brzina vertikalne deformacije od 30 mm/god., a u istom je razdoblju izmjerena i velika brzina deformacije od 40 mm/god
Investigation of spherical and cylindrical catural Iridium targets by photonuclear reaction
Calculation of (n,α) reaction cross sections by using some Skyrme force parameters for Potassium ( 41
Global, regional, and national prevalence and mortality burden of sickle cell disease, 2000-2021: a systematic analysis from the Global Burden of Disease Study 2021
BACKGROUND: Previous global analyses, with known underdiagnosis and single cause per death attribution systems, provide only a small insight into the suspected high population health effect of sickle cell disease. Completed as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021, this study delivers a comprehensive global assessment of prevalence of sickle cell disease and mortality burden by age and sex for 204 countries and territories from 2000 to 2021. METHODS: We estimated cause-specific sickle cell disease mortality using standardised GBD approaches, in which each death is assigned to a single underlying cause, to estimate mortality rates from the International Classification of Diseases (ICD)-coded vital registration, surveillance, and verbal autopsy data. In parallel, our goal was to estimate a more accurate account of sickle cell disease health burden using four types of epidemiological data on sickle cell disease: birth incidence, age-specific prevalence, with-condition mortality (total deaths), and excess mortality (excess deaths). Systematic reviews, supplemented with ICD-coded hospital discharge and insurance claims data, informed this modelling approach. We employed DisMod-MR 2.1 to triangulate between these measures-borrowing strength from predictive covariates and across age, time, and geography-and generated internally consistent estimates of incidence, prevalence, and mortality for three distinct genotypes of sickle cell disease: homozygous sickle cell disease and severe sickle cell β-thalassaemia, sickle-haemoglobin C disease, and mild sickle cell β-thalassaemia. Summing the three models yielded final estimates of incidence at birth, prevalence by age and sex, and total sickle cell disease mortality, the latter of which was compared directly against cause-specific mortality estimates to evaluate differences in mortality burden assessment and implications for the Sustainable Development Goals (SDGs). FINDINGS: Between 2000 and 2021, national incidence rates of sickle cell disease were relatively stable, but total births of babies with sickle cell disease increased globally by 13·7% (95% uncertainty interval 11·1-16·5), to 515 000 (425 000-614 000), primarily due to population growth in the Caribbean and western and central sub-Saharan Africa. The number of people living with sickle cell disease globally increased by 41·4% (38·3-44·9), from 5·46 million (4·62-6·45) in 2000 to 7·74 million (6·51-9·2) in 2021. We estimated 34 400 (25 000-45 200) cause-specific all-age deaths globally in 2021, but total sickle cell disease mortality burden was nearly 11-times higher at 376 000 (303 000-467 000). In children younger than 5 years, there were 81 100 (58 800-108 000) deaths, ranking total sickle cell disease mortality as 12th (compared to 40th for cause-specific sickle cell disease mortality) across all causes estimated by the GBD in 2021. INTERPRETATION: Our findings show a strikingly high contribution of sickle cell disease to all-cause mortality that is not apparent when each death is assigned to only a single cause. Sickle cell disease mortality burden is highest in children, especially in countries with the greatest under-5 mortality rates. Without comprehensive strategies to address morbidity and mortality associated with sickle cell disease, attainment of SDG 3.1, 3.2, and 3.4 is uncertain. Widespread data gaps and correspondingly high uncertainty in the estimates highlight the urgent need for routine and sustained surveillance efforts, further research to assess the contribution of conditions associated with sickle cell disease, and widespread deployment of evidence-based prevention and treatment for those with sickle cell disease. FUNDING: Bill & Melinda Gates Foundation
Effect of aliskiren on post-discharge outcomes among diabetic and non-diabetic patients hospitalized for heart failure: insights from the ASTRONAUT trial
Aims The objective of the Aliskiren Trial on Acute Heart Failure Outcomes (ASTRONAUT) was to determine whether aliskiren, a direct renin inhibitor, would improve post-discharge outcomes in patients with hospitalization for heart failure (HHF) with reduced ejection fraction. Pre-specified subgroup analyses suggested potential heterogeneity in post-discharge outcomes with aliskiren in patients with and without baseline diabetes mellitus (DM). Methods and results ASTRONAUT included 953 patients without DM (aliskiren 489; placebo 464) and 662 patients with DM (aliskiren 319; placebo 343) (as reported by study investigators). Study endpoints included the first occurrence of cardiovascular death or HHF within 6 and 12 months, all-cause death within 6 and 12 months, and change from baseline in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 1, 6, and 12 months. Data regarding risk of hyperkalaemia, renal impairment, and hypotension, and changes in additional serum biomarkers were collected. The effect of aliskiren on cardiovascular death or HHF within 6 months (primary endpoint) did not significantly differ by baseline DM status (P = 0.08 for interaction), but reached statistical significance at 12 months (non-DM: HR: 0.80, 95% CI: 0.64-0.99; DM: HR: 1.16, 95% CI: 0.91-1.47; P = 0.03 for interaction). Risk of 12-month all-cause death with aliskiren significantly differed by the presence of baseline DM (non-DM: HR: 0.69, 95% CI: 0.50-0.94; DM: HR: 1.64, 95% CI: 1.15-2.33; P < 0.01 for interaction). Among non-diabetics, aliskiren significantly reduced NT-proBNP through 6 months and plasma troponin I and aldosterone through 12 months, as compared to placebo. Among diabetic patients, aliskiren reduced plasma troponin I and aldosterone relative to placebo through 1 month only. There was a trend towards differing risk of post-baseline potassium ≥6 mmol/L with aliskiren by underlying DM status (non-DM: HR: 1.17, 95% CI: 0.71-1.93; DM: HR: 2.39, 95% CI: 1.30-4.42; P = 0.07 for interaction). Conclusion This pre-specified subgroup analysis from the ASTRONAUT trial generates the hypothesis that the addition of aliskiren to standard HHF therapy in non-diabetic patients is generally well-tolerated and improves post-discharge outcomes and biomarker profiles. In contrast, diabetic patients receiving aliskiren appear to have worse post-discharge outcomes. Future prospective investigations are needed to confirm potential benefits of renin inhibition in a large cohort of HHF patients without D
Antiinflammatory Therapy with Canakinumab for Atherosclerotic Disease
Background: Experimental and clinical data suggest that reducing inflammation without affecting lipid levels may reduce the risk of cardiovascular disease. Yet, the inflammatory hypothesis of atherothrombosis has remained unproved. Methods: We conducted a randomized, double-blind trial of canakinumab, a therapeutic monoclonal antibody targeting interleukin-1β, involving 10,061 patients with previous myocardial infarction and a high-sensitivity C-reactive protein level of 2 mg or more per liter. The trial compared three doses of canakinumab (50 mg, 150 mg, and 300 mg, administered subcutaneously every 3 months) with placebo. The primary efficacy end point was nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death. RESULTS: At 48 months, the median reduction from baseline in the high-sensitivity C-reactive protein level was 26 percentage points greater in the group that received the 50-mg dose of canakinumab, 37 percentage points greater in the 150-mg group, and 41 percentage points greater in the 300-mg group than in the placebo group. Canakinumab did not reduce lipid levels from baseline. At a median follow-up of 3.7 years, the incidence rate for the primary end point was 4.50 events per 100 person-years in the placebo group, 4.11 events per 100 person-years in the 50-mg group, 3.86 events per 100 person-years in the 150-mg group, and 3.90 events per 100 person-years in the 300-mg group. The hazard ratios as compared with placebo were as follows: in the 50-mg group, 0.93 (95% confidence interval [CI], 0.80 to 1.07; P = 0.30); in the 150-mg group, 0.85 (95% CI, 0.74 to 0.98; P = 0.021); and in the 300-mg group, 0.86 (95% CI, 0.75 to 0.99; P = 0.031). The 150-mg dose, but not the other doses, met the prespecified multiplicity-adjusted threshold for statistical significance for the primary end point and the secondary end point that additionally included hospitalization for unstable angina that led to urgent revascularization (hazard ratio vs. placebo, 0.83; 95% CI, 0.73 to 0.95; P = 0.005). Canakinumab was associated with a higher incidence of fatal infection than was placebo. There was no significant difference in all-cause mortality (hazard ratio for all canakinumab doses vs. placebo, 0.94; 95% CI, 0.83 to 1.06; P = 0.31). Conclusions: Antiinflammatory therapy targeting the interleukin-1β innate immunity pathway with canakinumab at a dose of 150 mg every 3 months led to a significantly lower rate of recurrent cardiovascular events than placebo, independent of lipid-level lowering. (Funded by Novartis; CANTOS ClinicalTrials.gov number, NCT01327846.
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